The present invention relates to a polymer dispersion type liquid crystal display panel used for a portable information terminal and a manufacturing method thereof, and particularly a polymer dispersion type liquid crystal display panel appropriately applicable to a display panel in a lateral electric field mode (IPS xe2x80x98In-plane Switching modexe2x80x99) and a manufacturing method thereof.
[1] In recent years, a polymer dispersion type liquid crystal display panel wherein a polymer and a liquid crystal composition are dispersed in an incompatible state is noticeable. Since the polymer dispersion type panel has such a characteristic that a polarizer is unnecessary and a display with a high luminance can be obtained easily because of using a scattering mode for displaying. (refer to S. Shikama et al, Society for Information Display ""95, pp. 231 to 234)
A polymer dispersion type panel is characterized by displaying by utilizing a refractive index matching of a liquid crystal and a polymer. A display mode of a polymer dispersion type panel is divided roughly into two kinds by a method of the refractive index matching. The one is a normal mode wherein a scattering display is executed under no application of voltage and a transparent display is executed under an application of voltage (for instance, the U.S. Pat. No. 3,600,060). The other is a reverse mode wherein a transparent display is executed under no application of voltage and a scattering display is executed under an application of voltage (for instance, Japanese Unexamined Patent Applications No. 2-309316 and No. 3-13268). Both of these two display modes are characterized by holding a polymer dispersion type liquid crystal between a pair of substrates with a transparent electrode and executing a switching of light by aligning a liquid crystal molecule in a vertical direction to the substrates under an application of voltage between the substrates.
Meanwhile, in the case of a liquid crystal panel wherein a display is executed by using a birefringence and a polarizer, a liquid crystal panel in a lateral electric field mode has been developed wherein an electric field is applied in parallel with a substrate for the purpose of a wide viewing angle (for instance, Japanese Unexamined Patent Publication No. 63-21907).
A liquid crystal panel is disclosed wherein an incident light is reflected into a gap between substrates by devising an electrode structure for intending a higher luminance with a lateral electric field mode (Japanese Unexamined Patent Publication No. 8-286211).
However, the above-mentioned conventional examples have various problems.
(1) A problem in a conventional polymer dispersion type liquid crystal panel
(a) In the case of using as a transmission type panel such as a projection type display, the panel has a defect of low contrast due to no disappearance of a black display resulting from insufficient scattering performance. Meanwhile, in order to solve such a defect, it is preferred to improve the scattering performance by increasing a panel gap and an optical length. However, the increase of a panel gap results in a high driving voltage, and the panel can not be utilized practically.
(b) In the case of using as a reflection type panel with a color filter such as a portable type display, the panel has a defect of low white luminance due to insufficient scattering of outside light in a white display resulting from insufficient scattering performance. Also in this case, the increase of a panel gap for improving the scattering performance results in a high driving voltage similarly to the above, and the panel can not be utilized practically.
(c) When a polymer dispersion type panel in a reverse mode as composed above is driven with a lateral electric field mode, a scattering intensity in applying voltage is increased, and a higher scattering and a higher contrast are obtained. Meanwhile, the problem is that a pixel aperture ratio is reduced and it is difficult to obtain a higher luminance since a driving electrode is arrayed in parallel at a pixel.
(2) A problem in a conventional liquid crystal display panel in a lateral electric field mode
(a) A luminance is low due to the use of a polarizer.
(b) An opaque electrode such as metal is usually used as an electrode used for applying an electric field in order to obtain a uniform display with a high contrast (refer to, for instance, M. Ohta et al, Proceedings of Asia Display ""95, pp.707 to 710). Accordingly, a pixel aperture ratio is low, approximately 30%, and the reduction of luminance is caused.
(c) When a gap between adjacent electrodes (equivalent to a gap in a direction of electric field between a first driving electrode and a second driving electrode in the present invention) is L (xcexcm) and a panel gap is d (xcexcm), the L and d usually satisfy L greater than d in view of the reduction of driving voltage, the improvement of panel luminance and the optimization of voltage-transmittance characteristic (refer to, for instance, M. Ohta et al, Proceedings of Asia Display ""95, pp. 577-580). Accordingly, a conventional panel in a lateral electric field mode using a nematic liquid crystal and a polarizer has the restriction in increasing the panel gap.
(d) When a conventional liquid crystal panel using a polarizer is driven with a lateral electric field mode, a wide viewing angle is actualized, while the problem is that a pixel aperture ratio is reduced and it is difficult to obtain a higher luminance due to a similar reason. As described in Japanese Unexamined Patent Publication No. 8-286211, in the case of composing so that a cross sectional form of a driving electrode is made a triangular form and incident light is reflected in a pixel aperture in order to intend a higher luminance, if an electrode exists in a liquid crystal layer, a black display does not disappear since an alignment direction of the liquid crystal is irregular on the side of the electrode, and a contrast gets lower. In the case of making an electrode a triangular form, a ratio h/W of its height h to its width W requires over 0.5. That is, in the case of electrode width W of 3 xcexcm, electrode height h requires over 1.5 xcexcm. Generally, a panel gap in a lateral electric field mode is 2 to 5 xcexcm. It is necessary to uniformize a panel gap with high precision. However, it is difficult to keep the panel gap below 5 xcexcm uniformly in a state of the electrode height of 1.5 xcexcm. Consequently, in the case of making an electrode form a triangular form with a conventional lateral electric field mode, it is necessary to form a flattened layer on an electrode completely Then, the flattened layer is, for instance, 1.6 xcexcm in thickness for covering the electrode. However, when the flattened layer is thick, the problem is that display irregularity occurs since an electric field is not applied uniformly to a liquid crystal layer.
[2] A conventional liquid crystal display panel has the following problems.
That is, various scattering type display panels have been discussed since before. PDLC (Polymer Dispersed Liquid Crystal) type liquid crystal display panel wherein a liquid crystal is dispersed into a polymer in a droplet (U.S. Pat. No. 4,688,900) and PNLC (Polymer Network Liquid Crystal) type liquid crystal display panel wherein a liquid crystal is dispersed into a polymer in a range of networks (No. 2724596 of Japanese Patent) are referred to as a typical example. In these conventional polymer dispersion type liquid crystal panels (hereinafter referred to as xe2x80x98the first conventional examplexe2x80x99), under an application of voltage, a liquid crystal molecule is aligned in a direction vertical to a substrate, and a refractive index of a liquid crystal molecule and a refractive index of a polymer are equalized, and thereby a transparent state is obtained. However, since a refractive index of a liquid crystal molecule and a refractive index of a polymer are different against a diagonal incident light, a sufficient transparent state is not obtained.
To solve the above-mentioned problems, a liquid crystal display panel hereinafter referred to as xe2x80x98the second conventional examplexe2x80x99), which is disclosed in U.S. Pat. No. 4,994,204 and Japanese Unexamined Patent Publication No. 2-503963, and a liquid crystal display panel (hereinafter referred to as xe2x80x98the third conventional examplexe2x80x99), which is disclosed in Japanese Unexamined Patent Publication No. 5-119302, are proposed
In the second conventional example, as shown in FIGS. 33(a) and (b), a liquid crystalline polymer 150 is used. The polymer 150 is aligned in a direction vertical to a substrate 151. Under no application of voltage, like a usual polymer dispersion type liquid crystal, as shown in FIG. 33(a), since a liquid crystal molecule 153 in a liquid crystal droplet 152 is aligned at random, a scattering state is obtained due to a mismatch between a refractive index of a liquid crystal molecule and a refractive index of a polymer.
Under an application of voltage, as shown in FIG. 33(b), a liquid crystal molecule 153 is aligned in a direction vertical to a substrate. When a refractive index in a major axis direction of a liquid crystal molecule 153 is made nlc ∥ and a refractive index in a minor axis direction nlc xe2x8axa5 and a refractive index in a major axis direction of a polymer 150 is made np ∥ and a refractive index in a minor axis direction np xe2x8axa5, nlc ∥ and np ∥ are determined so as to be equal, and nlc xe2x8axa5 and np xe2x8axa5 to be equal.
Therefore, as to a light 154 vertical to a substrate, a transparent state is obtained like a usual polymer dispersion type liquid crystal. Moreover, as to a diagonal light 155, since an angle of a light which transmits through the polymer 150 and an angle of a light which transmits through the liquid crystal molecule 153 are equal by the above-mentioned determination of a refractive index, a mismatch of a refractive index does not occur between the polymer 150 and the liquid crystal molecule 153. Consequently, the diagonal light 155 transmits through without being scattered. Thus, as to not only the light 154 vertical to a substrate but also the diagonal light 155, a transparent state is obtained.
The third conventional example is referred to as IRIS (Internal Reflection Inverted Scattering) type display panel wherein an alignment treatment is executed and a scattering state is obtained under an application of voltage.
In the third conventional example, as shown in FIGS. 34(a) and (b), a polymer 50 having a birefringence is used like the second conventional example. Under no application of voltage, a polymer 150 is aligned in a direction parallel with a substrate 151 and a liquid crystal molecule 153 is aligned in a direction parallel with the substrate 151 (FIG. 34(a)). Therefore, like the second conventional example, as to not only a light 154 vertical to a substrate but also a diagonal light 155, a transparent state is obtained.
Meanwhile, as shown in FIG. 34(b), under an application of voltage, a liquid crystal molecule 153 is aligned in an electric field direction (a direction vertical to a substrate). Thus, a refractive index of a liquid crystal molecule 153 and a refractive index of a polymer 150 are different against a light 154 vertical to a substrate, and a refractive index of a liquid crystal molecule 153 and a refractive index of a polymer 50 are different against a diagonal incident light 155.
Consequently, as to both a light 154 vertical to a substrate and a diagonal light 155, scattering occurs. Therefore, a scattering state is obtained under no application of voltage.
Thus, in the second and third conventional examples, since a transparent state is possible as to a diagonal light, a transparent characteristic improves in a transparent state.
However, the above-mentioned second and third conventional examples have the following problems.
(Problems in the second conventional example)
In the second conventional example, a scattering of a polymer dispersion type liquid crystal depends mainly on a scattering between a polymer and a liquid crystal.
As written in Japanese Unexamined Patent Publication No. 6-59246, a scattering between a liquid crystal and a liquid crystal is larger than a scattering between a polymer and a liquid crystal, and thereby the scattering between a liquid crystal and a liquid crystal is predominant in a scattering of a polymer dispersion type liquid crystal. Consequently, the problem is that a scattering intensity of a polymer dispersion type liquid crystal is not obtained sufficiently.
(Problems in the third conventional example)
In the third conventional example, besides the above-mentioned second conventional example, under no application of voltage, the problem is that a tint of an image differs between the case of watching in a direction parallel with an alignment direction of a polymer and a liquid crystal and the case of watching in a direction vertical to the alignment direction, in other words a coloration occurs, since all of a polymer and a liquid crystal are aligned in the same direction.
In addition, another problem is that an optical hysteresis is large and afterimage remains.
An optical hysteresis is an essential problem of a polymer dispersion type liquid crystal display panel including the first conventional example.
The present invention aims to solve the above-mentioned problems and provide a new polymer dispersion type liquid crystal display panel wherein a high contrast, a high luminance and a low power consumption can be intended.
In addition, the present invention, in consideration of the above-mentioned problems, aims to provide a polymer dispersion type liquid crystal display panel and a manufacturing method thereof wherein both an improvement of a transparent characteristic in a transparent state and an improvement of a scattering characteristic in a scattering state can be intended, and an influence of an optical hysteresis is reduced without a coloration.
In order to achieve the above-mentioned purpose, the invention according to claim 1 in the present invention is a polymer dispersion type liquid crystal display panel comprising a pair of substrates at least one of which is transparent, a polymer dispersion type liquid crystal layer composed of a polymer and a liquid crystal, which is held between the above-mentioned pair of substrates, and a first driving electrode and a second driving electrode which are provided at each pixel for applying an electric field to the above-mentioned polymer dispersion type liquid crystal layer and driving the polymer dispersion type liquid crystal layer as a light valve, wherein the above-mentioned polymer dispersion type liquid crystal layer is a polymer dispersion type liquid crystal layer with a high ratio of the liquid crystal to the polymer having a structure in which the liquid crystal is filled between the substrates and the polymer is dispersed into the filled liquid crystal so that the polymer and the liquid crystal can be aligned according to an alignment treatment of the substrates, the above-mentioned first driving electrode and the above-mentioned second driving electrode are formed on one of the above-mentioned pair of substrates in a disposition state of applying an electric field approximately in parallel with the above-mentioned substrates, and under no application of voltage the above-mentioned liquid crystal and the polymer, which is adjacent to the liquid crystal and composes an interface, are aligned in an approximately same direction on a plane parallel with the substrates according to an alignment treatment of the substrates as well as under an application of voltage the liquid crystal rotates on a plane parallel with the substrates and the polymer and the liquid crystal are in a disposition state of making an angle on a plane parallel with the substrates.
According to the above-mentioned composition, the liquid crystal and the polymer adjacent to the liquid crystal, which composes an interface, are aligned under no application of voltage in an approximately same direction on a plane parallel with the substrates. Therefore, a transparent state is obtained. The liquid crystal rotates on a plane parallel with the substrates under an application of voltage by the electric field parallel with the substrates. Therefore, a scattering state is obtained. Thus, it is possible to actualize a polymer dispersion type liquid crystal panel in a reverse mode using a lateral electric field mode. The following effect is produced by driving such a polymer dispersion type liquid crystal panel with a lateral electric field mode.
{circle around (1)}. It is possible to thicken a panel gap more than before without causing an increase in a driving voltage. The reason is that the driving voltage does not increase largely even if the panel gap increases since the driving voltage changes mainly depending on a distance between driving electrodes in the case of a lateral electric field mode.
{circle around (2)}. It is possible to intend a higher luminance and a higher contrast by thickening a panel gap. The reason is that scattering performance is improved largely since an optical length of light increases by increasing the panel gap.
A term xe2x80x98a ratio of a liquid crystalxe2x80x99 means a weight percentage of a liquid crystal in a polymer dispersion type liquid crystal layer.
The invention according to claim 2 is a polymer dispersion type liquid crystal display panel according to claim 1, wherein the above-mentioned polymer comprises a liquid crystalline polymer.
When a polymer comprises a liquid crystalline polymer, it is possible to increase a scattering intensity even more as compared with the case of comprising no liquid crystalline polymer. The reason is that the liquid crystal rotates on a plane parallel with the substrates under an application of voltage, and the polymer and the liquid crystal are in a disposition state of making an angle on a plane parallel with the substrates, and then, when the polymer is a liquid crystalline polymer, a birefringence occurs also in the polymer and a large scattering occurs resulting from an intensity and a direction of the birefringence of the liquid crystal and the liquid crystalline polymer.
As detailed in Embodiments, in the case of driving a polymer dispersion type liquid crystal panel with a lateral electric field mode, a scattering intensity increases remarkably as compared with a conventional longitudinal electric field mode if a polymer comprises a liquid crystalline polymer. Accordingly, when panel gaps are equal, a higher contrast is intended as compared with a conventional longitudinal electric field mode.
A term xe2x80x98a liquid crystalline polymerxe2x80x99 means a polymer having a birefringence.
The invention according to claim 3 is a polymer dispersion type liquid crystal display panel according to claim 1, wherein d greater than L is satisfied when a gap in a direction of an electric field between the above-mentioned first driving electrode and the above-mentioned second driving electrode is made L and a panel gap is made d.
According to the above-mentioned composition, it is possible to intend a higher luminance, a higher contrast and a lower voltage. The reason is described below.
d less than L is essential to a conventional lateral electric field mode because of optical designing.
Meanwhile, in a conventional polymer dispersion type panel, since a driving voltage is determined by a panel gap d, the increase of d for maintaining scattering performance (contrast) causes the increase of driving voltage accordingly. Therefore, it is impossible that the improvement of scattering performance and the reduction of driving voltage are compatible. As regards this point, in the present invention, the contrast can be raised by satisfying d greater than L without raising the driving voltage. The reason is that the increase of d does not cause the increase of driving voltage since the present invention is composed so as to drive a polymer dispersion type panel with a lateral electric field mode.
The invention according to claim 4 is a polymer dispersion type liquid crystal display panel according to claim 2, wherein d greater than L is satisfied when a gap in a direction of an electric field between the above-mentioned first driving electrode and the above-mentioned second driving electrode is made L and a panel gap is made d.
According to the above-mentioned composition, the same effect as the above-mentioned claim 3 is produced basically.
The invention according to claim 5 is a polymer dispersion type liquid crystal display panel according to claim 1, wherein the above-mentioned first driving electrode and the above-mentioned second driving electrode are transparent electrodes.
As described above, since the first driving electrode and the second driving electrode are transparent electrodes, a pixel aperture ratio gets higher. Consequently, a panel with a high luminance can be actualized.
The reason for using a transparent electrode in the present invention unlike a conventional lateral electric field mode is described below. A conventional lateral electric field mode uses such an opaque electrode as an aluminum plate for a driving electrode. This is because a uniform display can not be obtained since a liquid crystal right above the electrode does not move by an electric field or is distorted nonuniformly by an electric field nonuniformity at an end of the electrode. Meanwhile, in a polymer dispersion type liquid crystal panel, it is not always necessary that an electrode is opaque since an electric field nonuniformity at an end of the electrode is useful for the cause of scattering. As a characteristic of scattering mode, a slight nonuniformity of scattering characteristic right above the electrode or at an end of the electrode is averaged in the whole scattering, and does not cause display irregularity. Consequently, in the present invention in which a polymer dispersion type liquid crystal panel is used with a lateral electric field mode, a transparent electrode can be used as a driving electrode.
The invention according to claim 6 is a polymer dispersion type liquid crystal display panel according to claim 3, wherein the above-mentioned first driving electrode and the above-mentioned second driving electrode are transparent electrodes.
According to the above-mentioned composition, the same effect as the above-mentioned claim 5 is produced basically.
The invention according to claim 7 is a polymer dispersion type liquid crystal display panel according to claim 4, wherein the above-mentioned first driving electrode and the above-mentioned second driving electrode are transparent electrodes.
According to the above-mentioned composition, the same effect as the above-mentioned claim 5 is produced basically.
The invention according to claim 8 is a polymer dispersion type liquid crystal display panel according to claim 5, wherein a width of the above-mentioned first driving electrode and the above-mentioned second driving electrode is 6 xcexcm or less.
The reason for making the width 6 xcexcm or less is that a small width is effective in uniformizing a display since a liquid crystal right above the electrode has scattering by an electric field nonuniformity at an end of the electrode.
The invention according to claim 9 is a polymer dispersion type liquid crystal display panel according to claim 6, wherein a width of the above-mentioned first driving electrode and the above-mentioned second driving electrode is 6 xcexcm or less.
According to the above-mentioned composition, the same effect as the above-mentioned claim 8 is produced basically.
The invention according to claim 10 is a polymer dispersion type liquid crystal display panel according to claim 7, wherein a width of the above-mentioned first driving electrode and the above-mentioned second driving electrode is 6 xcexcm or less.
According to the above-mentioned composition, the same effect as the above-mentioned claim 8 is produced basically.
The invention according to claim 11 is a polymer dispersion type liquid crystal display panel according to claim 1, wherein an alignment of the liquid crystal in the polymer dispersion type liquid crystal layer is a homogeneous alignment under no application of voltage, in which a major axis of a liquid crystal molecule is approximately parallel with the substrates and the major axis is not twisted.
As described above, in the case of the homogeneous alignment, it is an advantage that the scattering under an application of voltage gets higher than the case of a twisted nematic alignment.
The invention according to claim 12 is a polymer dispersion type liquid crystal display panel according to claim 2, wherein an alignment of the liquid crystal in the polymer dispersion type liquid crystal layer is a homogeneous alignment under no application of voltage, in which a major axis of a liquid crystal molecule is approximately parallel with the substrates and the major axis is not twisted.
According to the above-mentioned composition, the same effect as the above-mentioned claim 11 is produced basically.
The invention according to claim 13 is a polymer dispersion type liquid crystal display panel according to claim 1, wherein an alignment of the liquid crystal in the polymer dispersion type liquid crystal layer is a twisted nematic alignment under no application of voltage, in which a major axis of a liquid crystal molecule is twisted successively between the substrates.
As described above, in the case of the twisted nematic alignment, it is an advantage that a viewing angle under no application of voltage gets wider than the case of a homogeneous alignment.
The invention according to claim 14 is a polymer dispersion type liquid crystal display panel according to claim 2, wherein an alignment of the liquid crystal in the polymer dispersion type liquid crystal layer is a twisted nematic alignment under no application of voltage, in which a major axis of a liquid crystal molecule is twisted successively between the substrates.
According to the above-mentioned composition, the same effect as the above-mentioned claim 13 is produced basically.
The invention according to claim 15 is a polymer dispersion type liquid crystal display panel according to claim 13, wherein a twist angle in the above-mentioned twisted nematic alignment is 180 degrees or more.
According to the above-mentioned composition, a display panel with a large viewing angle can be actualized.
The invention according to claim 16 is a polymer dispersion type liquid crystal display panel according to claim 14, wherein a twist angle in the above-mentioned twisted nematic alignment is 180 degrees or more.
According to the above-mentioned composition, the same effect as the above-mentioned claim 15 is produced basically.
The invention according to claim 17 is a polymer dispersion type liquid crystal display panel according to claim 11, wherein a dielectric anisotropy of the above-mentioned liquid crystal is positive, and an anglexcex8, which is formed by an alignment treatment direction of the above-mentioned substrates and the second driving electrode, is 45 degrees or less.
The reason for controlling the above-mentioned anglexcex8 is described below: when the anglexcex8 is small, an angle formed by the liquid crystal and the polymer in the case of rotating the liquid crystal under an application of voltage gets larger, and thereby a scattering intensity increases; meanwhile, when the anglexcex8 is large, an angle formed by the liquid crystal and the polymer under an application of voltage gets smaller, and thereby a sufficient scattering intensity can not be obtained.
The invention according to claim 18 is a polymer dispersion type liquid crystal display panel according to claim 12, wherein a dielectric anisotropy of the above-mentioned liquid crystal is positive, and an anglexcex8, which is formed by an alignment treatment direction of the above-mentioned substrates and the second driving electrode, is 45 degrees or less.
According to the above-mentioned composition, the same effect as the above-mentioned claim 17 is produced basically.
The invention according to claim 19 is a polymer dispersion type liquid crystal display panel according to claim 11, wherein a dielectric anisotropy of the above-mentioned liquid crystal is negative, and an anglexcex8, which is formed by an alignment treatment direction of the above-mentioned substrates and the second driving electrode, is 45 degrees or more and below 90 degrees.
The reason for controlling the above-mentioned anglexcex8 is basically the same as the reason for controlling the anglexcex8 in the above-mentioned invention according to claim 17: however, in the invention according to claim 19, since a dielectric anisotropy of the liquid crystal is negative, when the anglexcex8 is large, an angle formed by the liquid crystal and the polymer in the case of rotating the liquid crystal under an application of voltage gets larger, and thereby a scattering intensity increases; meanwhile, when the anglexcex8 is small, an angle formed by the liquid crystal and the polymer under an application of voltage gets smaller, and thereby a sufficient scattering intensity can not be obtained.
The invention according to claim 20 is a polymer dispersion type liquid crystal display panel according to claim 12, wherein a dielectric anisotropy of the above-mentioned liquid crystal is negative, and an anglexcex8, which is formed by an alignment treatment direction of the above-mentioned substrates and the second driving electrode, is 45 degrees or more and below 90 degrees.
According to the above-mentioned composition, the same effect as the above-mentioned claim 19 is produced basically.
The invention according to claim 21 is a polymer dispersion type liquid crystal display panel comprising a pair of substrates at least one of which is transparent, a polymer dispersion type liquid crystal layer composed of a polymer and a liquid crystal, which is held between the above-mentioned pair of substrates, and a first driving electrode and a second driving electrode which are provided at each pixel for applying an electric field to the above-mentioned polymer dispersion type liquid crystal layer and driving the polymer dispersion type liquid crystal layer as a light valve, wherein the above-mentioned polymer dispersion type liquid crystal layer is a polymer dispersion type liquid crystal layer in which the liquid crystal is a liquid crystal droplet and the liquid crystal droplet is dispersed into the polymer and a dielectric anisotropy of the liquid crystal is negative, the above-mentioned first driving electrode and the above-mentioned second driving electrode are formed on one of the above-mentioned pair of substrates in a disposition state of applying an electric field approximately in parallel with the above-mentioned substrates, and under no application of voltage an alignment direction of the liquid crystal in the above-mentioned liquid crystal droplet is aligned in a direction, which is approximately parallel with the substrates and approximately the same on a plane parallel with the substrates, as well as under an application of voltage the liquid crystal in the above-mentioned liquid crystal droplet is disposed on a plane parallel with a panel gap direction and an alignment direction of each liquid crystal droplet is disposed at random on a plane parallel with a panel gap direction.
According to the above-mentioned composition, under no application of voltage, since the alignment direction of the liquid crystal in the liquid crystal droplet is approximately parallel with the substrates, light scattering between the liquid crystal droplets does not occur and the panel in a transparent state is obtained. Under an application of voltage, since a dielectric anisotropy of the liquid crystal is negative, the liquid crystal is aligned on a plane parallel with a panel gap direction. Since an energy necessary for an inclination of a major axis of the liquid crystal in a direction vertical to an electric field direction does not depend on an azimuth angle and is equivalent in all directions, eventually the above-mentioned alignment direction of the liquid crystal in the liquid crystal droplet is disposed at random on a plane parallel with a panel gap direction. Then, the panel obtains a scattering state. Thus, when the liquid crystal is disposed at random in the panel gap direction, an effect of scattering a light crossing diagonally to the panel gap direction gets much higher.
The invention according to claim 22 is a polymer dispersion type liquid crystal display panel according to claim 21, wherein a liquid crystal alignment in the above-mentioned polymer dispersion type liquid crystal layer is obtained by applying an electric field parallel with the substrates while polymerizing the polymer.
When an electric field parallel with the substrates is applied while polymerizing the polymer, a liquid crystal droplet, in which a liquid crystal molecule is aligned along an electric field direction, is formed. Therefore, under an application of voltage, an alignment direction of the liquid crystal in the liquid crystal droplet is aligned in a direction, which is approximately parallel with the substrates and approximately the same on a plane parallel with the substrates.
The invention according to claim 23 is a polymer dispersion type liquid crystal display panel according to claim 21, wherein d greater than L is satisfied when a gap in a direction of an electric field between the above-mentioned first driving electrode and the above-mentioned second driving electrode is made L and a panel gap is made d.
By means of satisfying d greater than L, a higher luminance, a higher contrast and a lower voltage are intended by a similar function to the description of the above-mentioned invention according to claim 3.
The invention according to claim 24 is a polymer dispersion type liquid crystal display panel according to claim 1, wherein the above-mentioned first driving electrode and the above-mentioned second driving electrode are a comb-shaped electrode opposite to each other.
When the driving electrode is a comb-shaped electrode, the driving electrode can be disposed uniformly at a rectangular pixel and an effect of improving a pixel aperture ratio is produced.
The invention according to claim 25 is a polymer dispersion type liquid crystal display panel according to claim 2, wherein the above-mentioned first driving electrode and the above-mentioned second driving electrode are a comb-shaped electrode opposite to each other.
According to the above-mentioned composition, the same effect as the above-mentioned claim 24 is produced basically.
The invention according to claim 26 is a polymer dispersion type liquid crystal display panel according to claim 24, wherein the above-mentioned comb-shaped electrode has a shape in which a part of the electrode is bent.
In the case of using a shape in which a part of the electrode is bent, an effect of improving the scattering further is produced since a liquid crystal molecule rotates in a reverse direction on both sides of the bent part. A polarization dependence of scattered light by a viewing angle is averaged and a uniform characteristic of a viewing angle is obtained.
The invention according to claim 27 is a polymer dispersion type liquid crystal display panel according to claim 25, wherein the above-mentioned comb-shaped electrode has a shape in which a part of the electrode is bent.
According to the above-mentioned composition, the same effect as the above-mentioned claim 26 is produced basically.
The invention according to claim 28 is a polymer dispersion type liquid crystal display panel according to claim 24, wherein the above-mentioned comb-shaped electrode has a shape in which a corner of an electrode is roundish.
According to the above-mentioned composition, in the case of a shape in which a corner of an electrode is roundish, the nonuniformity of alignment at an electrode end is restrained and an effect of actualizing a uniform display performance is produced since an influence of the concentration of electric field on the corner is relaxed
The invention according to claim 29 is a polymer dispersion type liquid crystal display panel according to claim 25, wherein the above-mentioned comb-shaped electrode has a shape in which a corner of an electrode is roundish.
According to the above-mentioned composition, the same effect as the above-mentioned claim 28 is produced basically.
The invention according to claim 30 is a polymer dispersion type liquid crystal display panel comprising a pair of substrates at least one of which is transparent, a polymer dispersion type liquid crystal layer composed of a polymer and a liquid crystal, which is held between the above-mentioned pair of substrates, and a first driving electrode and a second driving electrode which are provided at each pixel for applying an electric field to the above-mentioned polymer dispersion type liquid crystal layer and driving the polymer dispersion type liquid crystal layer as a light valve, wherein the above-mentioned polymer dispersion type liquid crystal layer is a polymer dispersion type liquid crystal layer in which the liquid crystal is a liquid crystal droplet and the liquid crystal droplet is dispersed into the polymer and a dielectric anisotropy of the liquid crystal is positive, the above-mentioned first driving electrode and the above-mentioned second driving electrode are formed on one of the above-mentioned pair of substrates in a disposition state of applying an electric field approximately in parallel with the above-mentioned substrates, and under no application of voltage the liquid crystal in the above-mentioned liquid crystal droplet is aligned in a three-dimensionally random direction as well as under an application of voltage the liquid crystal in the above-mentioned liquid crystal droplet is aligned in a direction parallel with the substrates.
According to the above-mentioned composition, it is possible to actualize a polymer dispersion type liquid crystal display panel in a lateral electric field mode using a normal mode.
The invention according to claim 31 is a polymer dispersion type liquid crystal display panel comprising a pair of substrates which are transparent, a polymer dispersion type liquid crystal layer composed of a polymer and a liquid crystal, which is held between the above-mentioned pair of substrates, and a first driving electrode and a second driving electrode which are provided at each pixel for applying an electric field to the above-mentioned polymer dispersion type liquid crystal layer and driving the polymer dispersion type liquid crystal layer as a light valve, wherein the above-mentioned polymer dispersion type liquid crystal layer is a polymer dispersion type liquid crystal layer with a high ratio of the liquid crystal to the polymer having a structure in which the liquid crystal is filled between the substrates and the polymer is dispersed into the filled liquid crystal so that the polymer and the liquid crystal can be aligned according to an alignment treatment of the substrates, the above-mentioned first driving electrode and the above-mentioned second driving electrode are formed on one of the above-mentioned pair of substrates in a disposition state of applying an electric field approximately in parallel with the above-mentioned substrates and further have a shape in which at least a part of an incident light into the driving electrode can be reflected in a pixel aperture, and under no application of voltage the above-mentioned liquid crystal and the polymer, which is adjacent to the liquid crystal and composes an interface, are aligned in an approximately same direction on a plane parallel with the substrates according to an alignment treatment of the substrates as well as under an application of voltage the liquid crystal rotates on a plane parallel with the substrates and the polymer and the liquid crystal are in a disposition state of making an angle on a plane parallel with the substrates.
According to the above-mentioned composition, a light which transmits through a panel increases under no application of voltage and a higher luminance is actualized since at least a part of an incident light into the driving electrode can be reflected in a pixel aperture.
The invention according to claim 32 is a polymer dispersion type liquid crystal display panel according to claim 31, wherein the above-mentioned polymer comprises a liquid crystalline polymer.
According to the above-mentioned composition, in addition to the effect of the above-mentioned invention according to claim 31, a higher luminance and a higher contrast can be intended without increasing the driving voltage since the polymer comprises a liquid crystalline polymer.
The invention according to claim 33 is a polymer dispersion type liquid crystal display panel according to claim 31, wherein a cross sectional form of the above-mentioned first driving electrode and the above-mentioned second driving electrode is a triangular form so that at least a part of an incident light can be reflected in a pixel aperture.
According to the above-mentioned composition, an incident light into a panel can be reflected in a pixel aperture through the side of the triangle, and thereby a light which transmits through a panel increases under no application of voltage and a higher luminance is actualized.
The invention according to claim 34 is a polymer dispersion type liquid crystal display panel according to claim 32, wherein a cross sectional form of the above-mentioned first driving electrode and the above-mentioned second driving electrode is a triangular form so that at least a part of an incident light can be reflected in a pixel aperture.
According to the above-mentioned composition, the same effect as the above-mentioned claim 33 is produced basically.
The invention according to claim 35 is a polymer dispersion type liquid crystal display panel according to claim 31, wherein a cross sectional form of the above-mentioned first driving electrode and the above-mentioned second driving electrode is a trapezoidal form so that at least a part of an incident light can be reflected in a pixel aperture.
According to the above-mentioned composition, an incident light into a panel can be reflected in a pixel aperture through the side of the trapezoid, and thereby a light which transmits through a panel increases under no application of voltage and a higher luminance is actualized.
The invention according to claim 36 is a polymer dispersion type liquid crystal display panel according to claim 32, wherein a cross sectional form of the above-mentioned first driving electrode and the above-mentioned second driving electrode is a trapezoidal form so that at least a part of an incident light can be reflected in a pixel aperture.
According to the above-mentioned composition, the same effect as the above-mentioned claim 35 is produced basically.
The invention according to claim 37 is a polymer dispersion type liquid crystal display panel according to claim 33, wherein a flattened layer is formed on a substrate with the above-mentioned first driving electrode and the above-mentioned second driving electrode, a lower area of each driving electrode is covered with the above-mentioned flattened layer, and an upper area of each driving electrode projects into the above-mentioned polymer dispersion type liquid crystal layer.
According to the above-mentioned composition, it is possible to apply a uniform electric field to the polymer dispersion type liquid crystal layer as well as to reduce an alignment irregularity of the liquid crystal and the polymer by the irregularities of the electrodes.
The invention according to claim 38 is a polymer dispersion type liquid crystal display panel according to claim 34, wherein a flattened layer is formed on a substrate with the above-mentioned first driving electrode and the above-mentioned second driving electrode, a lower area of each driving electrode is covered with the above-mentioned flattened layer, and an upper area of each driving electrode projects into the above-mentioned polymer dispersion type liquid crystal layer.
According to the above-mentioned composition, the same effect as the above-mentioned claim 37 is produced basically.
The invention according to claim 39 is a polymer dispersion type liquid crystal display panel according to claim 35, wherein a flattened layer is formed on a substrate with the above-mentioned first driving electrode and the above-mentioned second driving electrode, a lower area of each driving electrode is covered with the above-mentioned flattened layer, and an upper area of each driving electrode projects into the above-mentioned polymer dispersion type liquid crystal layer.
According to the above-mentioned composition, the same effect as the above-mentioned claim 37 is produced basically.
The invention according to claim 40 is a polymer dispersion type liquid crystal display panel according to claim 36, wherein a flattened layer is formed on a substrate with the above-mentioned first driving electrode and the above-mentioned second driving electrode, a lower area of each driving electrode is covered with the above-mentioned flattened layer, and an upper area of each driving electrode projects into the above-mentioned polymer dispersion type liquid crystal layer.
According to the above-mentioned composition, the same effect as the above-mentioned claim 37 is produced basically.
The invention according to claim 41 is a polymer dispersion type liquid crystal display panel according to claim 31, wherein a flattened layer is formed on a substrate with the above-mentioned first and second driving electrodes, a lower area of each driving electrode is covered with the above-mentioned flattened layer, and an upper area of each driving electrode projects into the above-mentioned polymer dispersion type liquid crystal layer.
By means of satisfying d greater than L as the above-mentioned composition, a higher contrast and a lower voltage are intended.
The invention according to claim 42 is a polymer dispersion type liquid crystal display panel according to claim 32, wherein a flattened layer is formed on a substrate with the above-mentioned first and second driving electrodes, a lower area of each driving electrode is covered with the above-mentioned flattened layer, and an upper area of each driving electrode projects into the above-mentioned polymer dispersion type liquid crystal layer.
According to the above-mentioned composition, the same effect as the above-mentioned claim 41 is produced basically.
The invention according to claim 43 is a polymer dispersion type liquid crystal display panel comprising a pair of substrates, a polymer dispersion type liquid crystal layer composed of a polymer and a liquid crystal, which is held between the above-mentioned pair of substrates, and a first driving electrode and a second driving electrode which are provided at each pixel for applying an electric field to the above-mentioned polymer dispersion type liquid crystal layer and driving the polymer dispersion type liquid crystal layer as a light valve, wherein one of the above-mentioned pair of substrates is a transparent substrate and the other substrate forms a saw-toothed reflection layer inside the substrate, the above-mentioned polymer dispersion type liquid crystal layer is a polymer dispersion type liquid crystal layer with a high ratio of the liquid crystal to the polymer having a structure in which the liquid crystal is filled between the substrates and the polymer is dispersed into the filled liquid crystal so that the polymer and the liquid crystal can be aligned according to an alignment treatment of the substrates, the above-mentioned first driving electrode and the above-mentioned second driving electrode are formed on one of the above-mentioned pair of substrates in a disposition state of applying an electric field approximately in parallel with the above-mentioned substrates and further have a shape in which at least a part of an incident light into the driving electrode can be reflected at a different angle from a regular reflection direction when a light enters a plane parallel with the substrates, and under no application of voltage the above-mentioned liquid crystal and the polymer, which is adjacent to the liquid crystal and composes an interface, are aligned in an approximately same direction on a plane parallel with the substrates according to an alignment treatment of the substrates as well as under an application of voltage the liquid crystal rotates on a plane parallel with the substrates and the polymer and the liquid crystal are in a disposition state of making an angle on a plane parallel with the substrates.
According to the above-mentioned composition, it is possible to actualize a reflection type and polymer dispersion type liquid crystal display panel wherein a regularly reflected light in a reflection layer can be restrained, and a tone reversal and a reflection of peripheral light can be reduced.
The invention according to claim 44 is a polymer dispersion type liquid crystal display panel according to claim 43, wherein the above-mentioned polymer comprises a liquid crystalline polymer.
According to the above-mentioned composition, in addition to the effect according to the above-mentioned claim 43, a higher luminance and a higher contrast are intended without increasing the driving voltage since the polymer comprises a liquid crystalline polymer.
The invention according to claim 45 is a polymer dispersion type liquid crystal display panel according to claim 43, wherein a cross sectional form of the above-mentioned driving electrodes is a triangular form.
The invention according to claim 46 is a polymer dispersion type liquid crystal display panel according to claim 44, wherein a cross sectional form of the above-mentioned driving electrodes is a triangular form.
An incident light into a panel can be reflected in a pixel aperture through the side of the triangle.
The invention according to claim 47 is a polymer dispersion type liquid crystal display panel according to claim 45, wherein a flattened layer is formed on a substrate with the above-mentioned first and second driving electrodes, a lower area of each driving electrode is covered with the above-mentioned flattened layer, and an upper area of each driving electrode projects into the above-mentioned polymer dispersion type liquid crystal layer.
According to the above-mentioned composition, a uniform electric field can be applied to the polymer dispersion type liquid crystal layer as well as an alignment irregularity of the liquid crystal and the polymer by the irregularities of the electrodes can be reduced.
The invention according to claim 48 is a polymer dispersion type liquid crystal display panel according to claim 46, wherein a flattened layer is formed on a substrate with the above-mentioned first and second driving electrodes, a lower area of each driving electrode is covered with the above-mentioned flattened layer, and an upper area of each driving electrode projects into the above-mentioned polymer dispersion type liquid crystal layer.
According to the above-mentioned composition, the same effect as the above-mentioned claim 47 is produced basically.
The invention according to claim 49 is a polymer dispersion type liquid crystal display panel according to claim 43, wherein d greater than L is satisfied when a gap in a direction of an electric field between the above-mentioned first driving electrode and the above-mentioned second driving electrode is made L and a panel gap is made d.
By means of satisfying d greater than L as the above-mentioned composition, a higher contrast and a lower voltage are intended.
The invention according to claim 50 is a polymer dispersion type liquid crystal display panel according to claim 44, wherein d greater than L is satisfied when a gap in a direction of an electric field between the above-mentioned first driving electrode and the above-mentioned second driving electrode is made L and a panel gap is made d.
According to the above-mentioned composition, the same effect as the above-mentioned claim 49 is produced basically.
The invention according to claim 51 is a polymer dispersion type liquid crystal display panel wherein a polymer dispersion type liquid crystal layer comprising a liquid crystal and a polymer having a birefringence is held between a pair of substrates, and a display is executed by changing a light scattering state of the above-mentioned polymer dispersion type liquid crystal layer while applying an electric field in a predetermined direction to the polymer dispersion type liquid crystal layer with a means of applying an electric field, wherein an alignment treatment is executed on each of the above-mentioned pair of substrates so that the above-mentioned polymer is aligned in a predetermined direction, and under no application of voltage the above-mentioned liquid crystal is aligned so as to be along a wall surface of the above-mentioned polymer as well as under an application of voltage the above-mentioned liquid crystal is aligned in the same direction as an alignment direction of the above-mentioned polymer.
According to the above-mentioned composition, since the liquid crystal is aligned under no application of electric field so as to be along a wall surface of the polymer, the liquid crystal is aligned at random in view of the whole polymer dispersion type liquid crystal layer. Therefore, in addition to a scattering between a polymer and a liquid crystal, a scattering between a liquid crystal and a liquid crystal occurs and thereby a scattering intensity is improved. Meanwhile, since the liquid crystal is aligned under an application of electric field in the same direction as an alignment direction of the polymer, both an incident light vertical to a substrate and a diagonal incident light transmits through without being scattered when a refractive index of the liquid crystal is approximately equal to the refractive index of a polymer. Therefore, a transparency in a transparent state is improved. Consequently, it is possible to intend both an improvement of a transparent characteristic in a transparent state and an improvement of a scattering characteristic in a scattering state.
The invention according to claim 52 is a polymer dispersion type liquid crystal display panel according to claim 51, wherein an alignment treatment of the above-mentioned substrates is a vertical alignment treatment, and the above-mentioned liquid crystal has a positive dielectric anisotropy.
According to the above-mentioned composition, it is possible to intend both an improvement of a transparent characteristic in a transparent state and an improvement of a scattering characteristic in a scattering state. However, in the case of using an alignment layer for the alignment treatment of the substrates, a horizontal alignment is general as an alignment layer. Consequently, a choice of materials is limited in order to obtain a uniform alignment as a vertical alignment layer. As regards this point, a horizontal alignment layer has a merit such as an easy choice of materials and a high uniformity.
The invention according to claim 53 is a polymer dispersion type liquid crystal display panel according to claim 51, wherein an alignment treatment of the above-mentioned substrates is a horizontal alignment treatment, and the above-mentioned liquid crystal has a negative dielectric anisotropy.
According to the above-mentioned composition, the same effect as the above-mentioned claim 52 is produced basically.
The invention according to claim 54 is a polymer dispersion type liquid crystal display panel according to claim 51, wherein a weight ratio of the liquid crystal to the above-mentioned polymer dispersion type liquid crystal layer is 60% or more.
When the weight ratio of the liquid crystal is low, a transparency in a transparent state is reduced and additionally a scattering between a liquid crystal and a liquid crystal is not sufficiently obtained.
The invention according to claim 55 is a polymer dispersion type liquid crystal display panel according to claim 52, wherein a weight ratio of the liquid crystal to the above-mentioned polymer dispersion type liquid crystal layer is 60% or more.
According to the above-mentioned composition, the same effect as the above-mentioned claim 54 is produced basically.
The invention according to claim 56 is a polymer dispersion type liquid crystal display panel according to claim 53, wherein a weight ratio of the liquid crystal to the above-mentioned polymer dispersion type liquid crystal layer is 60% or more.
According to the above-mentioned composition, the same effect as the above-mentioned claim 54 is produced basically.
The invention according to claim 57 is a polymer dispersion type liquid crystal display panel according to claim 51, wherein the above-mentioned means of applying an electric field is a means of applying an electric field in a direction on a substrate plane.
According to the above-mentioned composition, a liquid crystal display panel in a lateral electric field mode is actualized.
The invention according to claim 58 is a polymer dispersion type liquid crystal display panel according to claim 57, wherein an alignment treatment of the above-mentioned substrates is a horizontal alignment treatment in which a horizontal alignment direction is approximately equal to an electric field direction of the above-mentioned means of applying an electric field, and the above-mentioned liquid crystal has a positive dielectric anisotropy.
According to the above-mentioned composition, a transparent characteristic in a transparent state is improved further.
The invention according to claim 59 is a method of manufacturing a polymer dispersion type liquid crystal display panel comprising the steps of forming a vertical alignment layer on a pair of substrates with an electrode, injecting a mixture in a solution comprising a liquid crystalline monomer and a liquid crystal material with a positive dielectric anisotropy between the pair of substrates after disposing the above-mentioned pair of substrates opposite, and forming a polymer dispersion type liquid crystal layer comprising a polymer which is aligned in a direction vertical to the substrates and a liquid crystal which is aligned so as to be along a wall surface of the polymer after phase-separating the polymer and the liquid crystal in a state in which the liquid crystalline monomer and the liquid crystal material in the above-mentioned mixture are aligned in a direction vertical to the substrates by an alignment treatment of the vertical alignment layer.
According to the above-mentioned composition, when the liquid crystalline monomer is used as a polymer precursor, the mixture in a solution indicates a liquid crystalline phase. The mixture is aligned in a direction of an alignment treatment of the substrates. Consequently, after polymerizing, the polymer is in a state of being aligned and fixed in the above-mentioned direction of an alignment treatment. Meanwhile, the liquid crystal is in a state of a random alignment, in view of the whole polymer dispersion type liquid crystal layer, by aligning the liquid crystal so as to be along a wall surface of the polymer. Therefore, a scattering between a liquid crystal and a liquid crystal is obtained and a liquid crystal display panel wherein a scattering intensity is improved can be actualized.
The invention according to claim 60 is a method of manufacturing a polymer dispersion type liquid crystal display panel comprising the steps of forming a horizontal alignment layer on a pair of substrates with an electrode, injecting a mixture in a solution comprising a liquid crystalline monomer and a liquid crystal material with a negative dielectric anisotropy between the pair of substrates after disposing the above-mentioned pair of substrates opposite, and forming a polymer dispersion type liquid crystal layer comprising a polymer which is aligned in a direction parallel with the substrates and a liquid crystal which is aligned so as to be along a wall surface of the polymer after phase-separating the polymer and the liquid crystal in a state in which the liquid crystalline monomer and the liquid crystal material in the above-mentioned mixture are aligned in a direction parallel with the substrates by an alignment treatment of the horizontal alignment layer.
According to the above-mentioned composition, it is possible to manufacture a liquid crystal display panel, wherein an improvement of a transparent characteristic in a transparent state and an improvement of a scattering characteristic in a scattering state can be intended.
The invention according to claim 61 is a method of manufacturing a polymer dispersion type liquid crystal display panel comprising the steps of forming a horizontal alignment layer on a substrate with a pair of comb-shaped electrodes and forming a horizontal alignment layer on the other substrate without an electrode, injecting a mixture in a solution comprising a liquid crystalline monomer and a liquid crystal material with a positive dielectric anisotropy between the substrates after disposing the above-mentioned substrate and the above-mentioned other substrate opposite, and forming a polymer dispersion type liquid crystal layer comprising a polymer which is aligned in a direction parallel with the substrates and a liquid crystal which is aligned so as to be along a wall surface of the polymer after phase-separating the polymer and the liquid crystal in a state in which the liquid crystalline monomer and the liquid crystal material in the above-mentioned mixture are aligned in a direction parallel with the substrates by an alignment treatment of the horizontal alignment layer.
According to the above-mentioned composition, it is possible to manufacture a liquid crystal display panel in an IPS mode, wherein an improvement of a transparent characteristic in a transparent state and an improvement of a scattering characteristic in a scattering state can be intended.
The invention according to claim 62 is a method of manufacturing a polymer dispersion type liquid crystal display panel according to claim 59, wherein the above-mentioned liquid crystalline monomer comprises a bi-functional monomer.
When the liquid crystalline monomer is a bi-functional monomer, the liquid crystal tends greatly to be aligned along a surface form of the polymer after polymerizing. The reason is detailed in Embodiments described below.
The invention according to claim 63 is a method of manufacturing a polymer dispersion type liquid crystal display panel according to claim 60, wherein the above-mentioned liquid crystalline monomer comprises a bi-functional monomer.
According to the above-mentioned composition, the same effect as the above-mentioned claim 62 is produced basically.
The invention according to claim 64 is a method of manufacturing a polymer dispersion type liquid crystal display panel according to claim 61, wherein the above-mentioned liquid crystalline monomer comprises a bi-functional monomer.
According to the above-mentioned composition, the same effect as the above-mentioned claim 62 is produced basically.
The invention according to claim 65 is a method of manufacturing a polymer dispersion type liquid crystal display panel according to claim 59, wherein a heat treatment is executed on the polymer dispersion type liquid crystal layer after a step of forming the above-mentioned polymer dispersion type liquid crystal layer.
It was confirmed that a part of the liquid crystal was not aligned along a surface form of the polymer in a step of forming the polymer dispersion type liquid crystal layer in the case of a low content of the bi-functional monomer in the liquid crystalline monomer. It was confirmed that a polymerization was promoted and the above-mentioned part of the liquid crystal tended to be aligned along a surface form of the polymer by further executing a heat treatment even in such a state. Consequently, it is possible to obtain a liquid crystal display panel with the same scattering characteristic as a liquid crystal display panel manufactured in the case of a proper content of the bi-functional monomer.
The invention according to claim 66 is a method of manufacturing a polymer dispersion type liquid crystal display panel according to claim 60, wherein a heat treatment is executed on the polymer dispersion type liquid crystal layer after a step of forming the above-mentioned polymer dispersion type liquid crystal layer.
According to the above-mentioned composition, the same effect as the above-mentioned claim 65 is produced basically.